Her idea? Hotels can eliminate the need for room key cards by emailing unique barcodes to guests' smart phones.

"You could then scan your phone against the lock to enter your room," Harrington said in describing her idea on the website travelbrilliantly.com.

"This would avoid the hassles of having to deal with late arrivals and obtaining keys," she said.

Harrington, who designs software for clinical trial management systems, said she couldn't find anything like the barcode system when she searched the Internet.

The idea had already occurred to her a few months before she got an email in mid-September about the contest from the Marriott Rewards program, she said.

"I thought it would be the perfect opportunity to add my voice, to make a suggestion to possibly innovate the way we check in," she said.

Harrington said she travels at least five or six times a year, either for business or vacation with her husband and two sons.

Receiving a key via a smart phone is easier than keeping track of key cards and allows hotel guests to check in online no matter what time they arrive, she said.

"Most people carry their phones with them everywhere so it seemed like a logical next step," she said.

For those who don't use smart phones, the lock would still need to work with a key card, said Harrington, 39, who grew up in New Orleans and has lived in Sugar Land for seven years.

The key card could also contain a unique barcode that could be held up to the lock, she said.

The contest is part of Marriott's new Travel Brilliantly global marketing campaign "amplifying the brand's dedication to leading the future of travel," the company said in its announcement.

The campaign includes a new look and logo, multiple forms of advertising and a new website, www.travelbrilliantly.com, where customers can learn about innovations under development and also submit ideas.

Harrington's submission, along with the 14 other finalists' ideas, will be judged Sept. 30 by judges Shira Lazar, host and co-founder of "What's Trending;" Marc Kushner, founder and chief executive officer of Architizer.com; and Matthew Von Ertfelda, Marriott's vice president of creative strategy.

Whoever wins the contest will have a chance to travel internationally and work with Marriott Hotels to refine their idea, the company said.